Physical Development in Middle Childhood

Younger Girls

• As girls enter the middle childhood years, they will continue growing at a steady pace. On average, your daughter will grow approximately 2.5 inches and gain 4 to 7 pounds each year until she begin puberty, notes KidsHealth from Nemours. During this period, she may begin to worry or have feelings about her growth and how she looks, especially if she begins developing breasts earlier than normal. There is no need for concern unless breasts beginning developing younger than age 6 for African American girls or age 7 for Caucasian girls, notes HealthyChildren.org.

Older Girls

• Later on in the middle childhood years, girls typically begin to develop breast buds. This normally occurs between the ages of 8 and 13, states KidsHealth. Your daughter may be unprepared for this and feel like something is wrong with her body, since this development can sometimes cause pain and tenderness -- again, this is normal. Next, pubic hair usually begins to grow, starting out sparse and straight, then turning coarser and curlier. Menstruation will typically begin around one and a half to three years after your daughter's breasts develop. Along with puberty may come some weight gain. This weight, which is often referred to as "baby fat," normally causes a slightly rounded abdomen at first. Eventually, her body will use this fat to create a more womanly figure, particularly in the hips and breasts.

Younger Boys

• Just like younger age girls, boys entering middle childhood will steadily grow, gaining approximately 4 to 7 pounds and growing about 2.5 inches each year, until puberty starts. Like girls, at this stage boy's muscle mass will begin to increase and coordination and strength will improve, according to HealthyChildren.org. By the time your son reaches age 5, he will likely be able to walk on his tiptoes and skip. At age 6, he will be able to ride a bike and dress himself.

Older Boys

• Boys begin puberty on their body's own schedule, usually starting between the ages of 10 and 16. Two boys that are the same age may start puberty years apart, notes HealthyChildren.org, and this is completely normal. The onset of puberty brings an increase in testicles and penis size, along with pubic hair. Underarm hair and facial hair follows. During puberty, your son's voice starts to get deeper and his larynx cartilage, also known as the Adam's apple, will start getting larger. Within one year of his testicles enlarging, he will begin producing sperm and testosterone. His body shape will change during this period of his life as well. Boys also tend to experience a dramatic height increase and begin building more muscle mass.